<template>
  <el-color-picker v-model="theme" :predefine="predefineColors" class="theme-picker" popper-class="theme-picker-dropdown" />
</template>

<script>
const version = require('element-ui/package.json').version // element-ui version from node_modules
const ORIGINAL_THEME = '#409EFF' // default color
export default {
  data() {
    return {
      chalk: '', // content of theme-chalk css
      theme: '',
      predefineColors: [
        '#1890ff',
        '#304156',
        '#212121',
        '#15a362',
        '#0DB5C8',
        '#6959CD',
        '#161084',
        '#f5222d',
        '#F1635F',
        '#ff4500',
        '#ff8c00',
        '#ffd700',
        '#90ee90',
        '#c71585'
      ]
    }
  },
  computed: {
    defaultTheme() {
      return this.$store.getters.themeColor
    }
  },
  watch: {
    defaultTheme: {
      // eslint-disable-next-line no-unused-vars
      handler: function (val, oldVal) {
        this.theme = val
      },
      immediate: true
    },
    async theme(val) {
      const oldVal = this.chalk ? this.theme : ORIGINAL_THEME
      if (typeof val !== 'string') return
      localStorage.setItem('colorPicker', val)
      const themeCluster = this.getThemeCluster(val.replace('#', ''))
      const originalCluster = this.getThemeCluster(oldVal.replace('#', ''))

      const $message = this.$message({
        message: '  Compiling the theme',
        customClass: 'theme-message',
        type: 'success',
        duration: 500,
        iconClass: 'el-icon-loading'
      })

      const getHandler = (variable, id) => {
        return () => {
          const originalCluster = this.getThemeCluster(
            ORIGINAL_THEME.replace('#', '')
          )
          const newStyle = this.updateStyle(
            this[variable],
            originalCluster,
            themeCluster
          )

          let styleTag = document.getElementById(id)
          if (!styleTag) {
            styleTag = document.createElement('style')
            styleTag.setAttribute('id', id)
            document.head.appendChild(styleTag)
          }
          styleTag.innerText = newStyle
        }
      }

      if (!this.chalk) {
        // 内网环境下将css文件放在服务器切换 url地址到服务器文件上进行访问
        try {
          // 外网
          const url = `https://unpkg.com/element-ui@${version}/lib/theme-chalk/index.css`
          // const url = `https://cdn.bootcdn.net/ajax/libs/element-ui/${version}/theme-chalk/index.css`
          const res = await this.getCSSString(url, 'chalk')
          if (!res) {
            const url = `https://cdn.bootcdn.net/ajax/libs/element-ui/${version}/theme-chalk/index.css`
            await this.getCSSString(url, 'chalk')
          }
        } catch (error) {
          // 内网
          this.$axios.get('/dobo-template/static/css/theme.css').then((res) => {
            this['chalk'] = res.data.replace(/@font-face{[^}]+}/, '')
          })
        }
      }
      const chalkHandler = getHandler('chalk', 'chalk-style')

      chalkHandler()

      const styles = [].slice
        .call(document.querySelectorAll('style'))
        .filter((style) => {
          const text = style.innerText
          return (
            new RegExp(oldVal, 'i').test(text) && !/Chalk Variables/.test(text)
          )
        })
      styles.forEach((style) => {
        const { innerText } = style
        if (typeof innerText !== 'string') return
        style.innerText = this.updateStyle(
          innerText,
          originalCluster,
          themeCluster
        )
      })

      this.$emit('change', val)
      $message.close()
    }
  },
  mounted() {
    if (localStorage.getItem('colorPicker')) {
      if (this.CheckIsColor(localStorage.getItem('colorPicker'))) {
        this.theme = localStorage.getItem('colorPicker')
      }
    } else {
      this.theme = '#1891FF'
    }
  },

  methods: {
    CheckIsColor(bgVal) {
      var type = '^#[0-9a-fA-F]{6}$'
      var re = new RegExp(type)
      if (bgVal.match(re) == null) {
        type =
          // eslint-disable-next-line no-useless-escape
          '^[rR][gG][Bb][(]([\\s]*(2[0-4][0-9]|25[0-5]|[01]?[0-9][0-9]?)[\\s]*,){2}[\\s]*(2[0-4]\\d|25[0-5]|[01]?\\d\\d?)[\\s]*[)]{1}$'
        re = new RegExp(type)
        if (bgVal.match(re) == null) {
          return false
        } else {
          return true
        }
      } else {
        return true
      }
    },
    updateStyle(style, oldCluster, newCluster) {
      let newStyle = style
      oldCluster.forEach((color, index) => {
        newStyle = newStyle.replace(new RegExp(color, 'ig'), newCluster[index])
      })
      return newStyle
    },
    getCSSString(url, variable) {
      return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest()
        xhr.onreadystatechange = () => {
          if (xhr.readyState === 4 && xhr.status === 200) {
            this[variable] = xhr.responseText.replace(/@font-face{[^}]+}/, '')
            resolve(true)
          } else {
            resolve(false)
          }
        }
        xhr.open('GET', url)
        xhr.send()
      })
    },
    getThemeCluster(theme) {
      const tintColor = (color, tint) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)

        if (tint === 0) {
          // when primary color is in its rgb space
          return [red, green, blue].join(',')
        } else {
          red += Math.round(tint * (255 - red))
          green += Math.round(tint * (255 - green))
          blue += Math.round(tint * (255 - blue))

          red = red.toString(16)
          green = green.toString(16)
          blue = blue.toString(16)

          return `#${red}${green}${blue}`
        }
      }

      const shadeColor = (color, shade) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)

        red = Math.round((1 - shade) * red)
        green = Math.round((1 - shade) * green)
        blue = Math.round((1 - shade) * blue)

        red = red.toString(16)
        green = green.toString(16)
        blue = blue.toString(16)

        return `#${red}${green}${blue}`
      }

      const clusters = [theme]
      for (let i = 0; i <= 9; i++) {
        clusters.push(tintColor(theme, Number((i / 10).toFixed(2))))
      }
      clusters.push(shadeColor(theme, 0.1))
      return clusters
    }
  }
}
</script>

<style>
.theme-message,
.theme-picker-dropdown {
  z-index: 99999 !important;
}

.theme-picker .el-color-picker__trigger {
  height: 28px !important;
  width: 28px !important;
  padding: 0 !important;
  border: none !important;
}

.theme-picker-dropdown .el-color-dropdown__link-btn {
  display: none;
}
.el-color-picker__color {
  border: none !important;
}
.el-color-picker__color-inner {
  border-radius: 3px !important;
}
</style>
